package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCDemo8 {
    public static void main(String[] args) {
        try (Connection connection = DBUtil.getConnection();){
            Statement statement = connection.createStatement();
            String sql = "SELECT COUNT(*) count,c.name " +
                    "FROM student s " +
                    "JOIN class c ON s.class_id = c.id " +
                    "GROUP BY c.name ";
            ResultSet rs = statement.executeQuery(sql);
            while (rs.next()) {
                int count = rs.getInt("count");
                String name = rs.getString("c.name");
                System.out.println("人数:" + count + ",班级:" + name);

            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}
